1. Field of the Invention
This invention relates to superconductive articles. Specifically, the invention relates to superconductive cables having an alkali metal activated cobalt phthalocyanine material coated on the outer surface therof to impart the superconductive characteristics thereto.
2. Description of the Prior Art
Superconductive articles such as cables for the transmission of electricity are well known. In the fabrication of such articles certain material such as nobium can advantageously be used in the form of a thin layer which is deposited on a tubular shaped metal of high normal electric conductivity (see U.S. Pat. No. 4,060,693). Aluminum in very pure form is particularly well suited as the tubular shaped metal. The use of such composite superconducting cables has been recognized, see for example, German Offenlengungschrift No. 1,814,036, and Bulletin of the Schweizerischer Elektrotechnischer Verein (Swiss Society of Electrical Engineers) Vo. 61 (1970), pp. 1179 to 1190. As shown in U.S. Pat. No. 3,657,467 electrical cables have also heretofore been fabricated utilizing electrically normal conducting metals joined in good electrically conductive and heat conductive relation to superconductors. To this end superconductors have been embedded in the electrically normal conductive metals or in other fashions connected electrically in parallel with electrically normal conductive metals.
In accordance with the present invention, I have discovered that a superconductive article suitable for transmission of electric current can be obtained by coating an electrically normal conductive cable with a layer comprising cobalt phthalocyanine and an alkali metal. The ratio of alkali metal atoms to cobalt phthalocyanine molecules in the layer is suitably about 8:1, the electrically normal conductive metal cable preferably comprises aluminum; and, the cable is suitably of hollow configuration.
Utilizing the alkali metal-activated cobalt phthalocyanine coated cable of the present invention allows for attainment of superconductivity at temperatures above those provided by liquid or cold helium in the gaseous state. In accordance with applicant's invention superconductivity can be obtained at the boiling point of liquid nitrogen. Suitably, superconductivity can be obtained utilizing fluids having a boiling temperature of under about 150.degree. K., such as liquid hydrogen, liquid nitrogen or other cooling mediums providing corresponding temperatures.
It is, therefore, a principal object of this invention to provide a superconductive cable of current-carrying ability, which cable operates as a superconductor at temperatures above the boiling point of liquid helium.